JPH09239666A - Smoothing tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the smoothing tool which can remove the crack layer of a work piece caused by grinding with high accuracy in shape and efficiently regardless of the shape of the work piece. SOLUTION: An elastic member 3 such as silicone rubber and the like, is bonded onto the surface of the base substrate 2 of the smoothing tool 1, and furthermore, a surface member 4 made out of epoxy resin and the like, is also bonded onto the surface of the elastic member 3. A mounting part 5 is provided for the upper part of the base substrate 2, and the mounting part 5 in then combined with the shaft of a polishing machine. The aforesaid smoothing tool 1 is designed for an aspherical convex lens, and the curvature of a spheric surface for the base substrate 2, the elastic member 3 and the surface member 4, is made identical to a spheric surface to which the processing surface of a work piece having an aspheric surface, is approximated. When a smoothing process is performed, slurry in which abrasive grains are dispersed in polishing agent such as water and the like, is coated to the processing surface of the work piece in advance, the work piece is then rotated, and concurrently the smoothing tool 1 is reciprocated so as to be pressed on to the processing surface as specified while being rotated, so that the crack layer of the processing surface is thereby efficiently removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a smoothing tool used for smoothing optical elements such as lenses and mirrors, and particularly to a smoothing tool suitable for processing aspherical optical elements.
It is related to the jig tool.

[0002]

2. Description of the Related Art As a general example of processing an optical element into an aspherical surface, a conventional aspherical surface processing method includes a uniform polishing processing method and a small tool polishing processing method. In the uniform polishing method, after grinding the work piece, a grinding plate (balloon-shaped, that is pressed against the entire work surface of the work piece) that is sufficiently larger than the work piece under certain processing conditions is used. The crack layer generated by grinding is removed. In the uniform polishing method,
Since the polishing pressure, polishing rate, polishing agent, etc. are not uniform, it is difficult to perform uniform polishing. Therefore, in general, make sure that the shape of the workpiece after uniform polishing is the design value in advance. Grinding is finished by taking into account the error caused by uniform polishing in the shape of the workpiece after grinding.

In the small tool polishing method, after grinding a work piece, a polishing dish (polisher) sufficiently smaller than the work piece is used for a long time after grinding the work piece. To remove the crack layer on the machined surface.

[0004]

However, in the above uniform polishing method, the crack layer can be removed in a short time. However, in order to completely grasp the uniform polishing error, many reproductions are required. However, the shape after uniform polishing does not always have a perfect design value because a reproducibility error is added. In addition, it may not be possible to estimate the amount of error depending on the shape of the workpiece.

On the other hand, with the small tool polishing method, polishing can be performed regardless of the shape of the work, but it takes a long time to remove the crack layer of the work, and efficient work cannot be performed. .

The present invention solves the above problems and provides a smoothing tool capable of removing a crack layer of a work piece generated by grinding with high shape accuracy and efficiently regardless of the shape of the work piece. The purpose is to

[0007]

A first aspect of the present invention is a smoothing tool for smoothing by sliding on a working surface while supplying a liquid containing abrasive grains to the working surface of a workpiece. , The diameter of the smoothing tool is smaller than that of the workpiece, and a resin is used for the surface member of the smoothing tool that is pressed against the workpiece (claim 1).

Since the surface member of the small-sized smoothing tool which is pressed against the work piece is made of resin, the surface member is deformed following the shape of the work surface of the work piece. Since it is pressed uniformly, the machined surface can be efficiently and smoothly finished. Further, since a smoothing tool having a small diameter is slid on the machined surface for smoothing, machining can be performed regardless of the shape of the machined surface such as an aspherical surface. The hardness of the resin used for the surface member is preferably in the range of Shore hardness D50 to 90. When it is harder than this range, the followability of the surface member shape to the machined surface shape is deteriorated, while when it is softer than this range, the working force of the smoothing tool is lowered. Further, as the type of resin, epoxy resin, engineering plastic, etc. are preferable.

In the first aspect of the present invention, it is preferable that an elastic member is provided between the surface member and the base body of the smoothing tool that supports the surface member. When the elastic member is provided, the resilience or resilience of the elastic member further improves the conformability of the surface member shape to the processed surface shape, and the surface member is pressed against the processed surface of the workpiece with a uniform surface pressure. It

Further, in the above, when the processed surface of the workpiece is an aspherical surface, the surface shape of the substrate supporting the surface member of the smoothing tool and / or the surface shape of the surface member is
It is preferable that the aspherical surface of the machined surface has a spherical shape when approximated by a spherical surface. In this case, the surface member is easily brought into close contact with the aspherical surface to be machined, and the layer thickness of the surface member or the like becomes uniform, so that the surface pressure becomes uniform over the entire surface member. The error between the aspherical surface of the processed surface and the spherical surface of the surface member is corrected by the deformation of the surface member shape. As a method of approximating an aspherical surface with a spherical surface, the least square method or the like is used.

Further, in the above, when the mesh-shaped groove is formed on the surface of the surface member, the abrasive grains are held or stored in the groove, and effective processing is performed.

A second aspect of the present invention is a smoothing tool for smoothing by sliding on the working surface while supplying a liquid such as water to the working surface of the workpiece. The diameter of the work piece is smaller than that of the work piece, and the fixed abrasive grains mixed with the resin and the abrasive grains are used for the surface member of the smoothing tool that is brought into pressure contact with the work piece (claim 6).

Since the fixed abrasive containing a mixture of resin and abrasive grains is used for the surface member, the surface member is deformed following the shape of the processed surface of the workpiece, and the surface member is uniformly pressed against the processed surface. The fixed abrasive grains efficiently and smoothly finish the machined surface. Furthermore, it is not necessary to supply a liquid containing abrasive grains to the entire processed surface, and the amount of expensive abrasive grains such as diamond used can be reduced.

Also in the second invention, similarly to the first invention, it is preferable to provide an elastic member between the surface member and the base body of the smoothing tool supporting the surface member.
Furthermore, when the processed surface of the workpiece is an aspherical surface, when the surface shape of the substrate and / or the surface shape of the surface member that supports the surface member of the smoothing tool is approximated by a spherical surface to the aspherical surface of the processed surface. The spherical shape is preferable.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a smoothing tool of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 is a smoothing tool having a substantially cylindrical shape as a whole,
The diameter is sufficiently smaller than the work piece. Sum-
The base 2 of the jig tool 1 is made of an aluminum alloy or an iron alloy. An elastic member 3 made of silicone rubber or urethane rubber is adhered to the surface of the bottom of the base body 2, and a surface member 4 made of epoxy resin or the like is adhered to the surface of the elastic member 3.

A mounting portion 5 is provided on the upper portion of the base body 2, and as shown in FIG. 2, the mounting portion 5 is mounted on the swing shaft 6 of the polishing machine. A sticking plate 9 is attached to the lower shaft 10 of the polishing machine, and the workpiece 7 is stuck on the sticking plate 9. Workpiece 7 of this embodiment
Is an aspherical convex lens, and the surfaces of the base body 2, the elastic member 3 and the surface member 4 are concave spherical surfaces according to the shape of the processed surface 8 of the aspherical surface. The curvature of the spherical surface of the base 2, the elastic member 3, and the surface member 4 is the same as the curvature of the spherical surface when the aspherical surface of the processed surface 8 is approximated by a spherical surface.

In the smoothing process, as shown in FIG. 2, the lower shaft 10 rotates the workpiece 7 at a constant speed, and the swing shaft 6 rotates the smoothing tool 1 at a constant speed. The processed surface 8 is pressed with a predetermined pressure.
At this time, a slurry in which abrasive grains such as alumina or diamond powder are dispersed in a polishing liquid such as water is applied to the processed surface 8 of the workpiece 7 in advance. Then, by reciprocally swinging the smoothing tool 1 along the scanning locus 11 at a predetermined feed speed, the crack layer of the machined surface 8 generated during grinding is efficiently removed.

At this time, the surface member 4 of the smoothing tool 1
The resin layer is deformed following the shape of the processed surface 8, and the surface member 4 is uniformly pressed against the processed surface 8. Further, the restoring force (reaction force) of the elastic member 3 presses the surface member 4 against the processed surface 8 with a uniform surface pressure. Further, since the surface shape of the surface member 4 is a spherical surface which is an aspherical surface approximation of the processed surface 8, the surface member 4 is brought into close contact with the processed surface 8 and the layer thickness of the surface member 4 and the elastic member 3 is uniform. The surface pressure for 8 becomes substantially uniform over the entire surface member 4.

[0019]

EXAMPLE An example in which the above embodiment is embodied will be described below. In this example, an epoxy resin is used as the resin of the surface member 4 of the above-described embodiment, and the surface of the surface member 4 is formed as shown in FIG.
The mesh-shaped groove 12 as shown in FIG. Further, as the slurry, one having alumina having a particle size of 1200 dispersed in water was used. Then, the smoothing tool 1 is rotated 35 times /
Smoothing was performed by rotating the aspherical workpiece 7 at 30 revolutions / minute while rotating the workpiece for 7 minutes.

When processing was performed under these conditions, extremely efficient processing results were obtained in smoothing, which is positioned as the next step of grinding. Abrasive grains are taken into the grooves 12 formed in the surface member 4, and the taken-in abrasive grains effectively cause a working action, so that the working efficiency is improved.

Further, processing was also carried out using a fixed abrasive grain surface member in which an epoxy resin and alumina abrasive grains were mixed, but it was confirmed that the abrasive grains were fixed to the surface member and the resin layer of the surface member. The processing efficiency was further improved due to the increase in hardness.

[0022]

As described above, according to the present invention, the surface member of the small-diameter smoothing tool which is pressed against the workpiece is a resin such as epoxy resin (claim 1). Since the surface member is deformed following the shape of the processed surface of the workpiece, the surface member is pressed uniformly against the processed surface, and the processed surface can be quickly and smoothly finished.
Further, since the smoothing tool having a small diameter is slid on the processing surface to smooth the surface, it is possible to perform processing with high accuracy regardless of the shape of the processing surface such as an aspherical surface. For this reason,
In particular, since the crack layer can be removed efficiently and accurately after grinding, the processing time of the next step (polishing) can be significantly reduced, which can contribute to the reduction of the manufacturing cost of the aspherical optical element.

In the above, when an elastic member is provided between the surface member and the base body of the smoothing tool that supports the surface member (claim 2), the restoring force or elastic force of the elastic member causes
The followability of the shape of the surface member to the shape of the processed surface is further improved, and the surface member is pressed against the processed surface of the workpiece with a uniform surface pressure to efficiently and smoothly finish the surface.

Further, in the above, when the processed surface of the workpiece is an aspherical surface, the surface shape of the substrate supporting the surface member of the smoothing tool and / or the surface shape of the surface member is
If the aspherical surface of the machined surface has a spherical shape when approximated by a spherical surface (Claim 3), the surface member is easily brought into close contact with the machined surface of the aspherical surface, and the layer thickness of the surface member becomes uniform. The surface pressure becomes uniform over the entire surface of the member, and the processed surface can be smoothed without degrading the shape accuracy.

Further, in the above, by forming the mesh-like grooves on the surface of the surface member (claim 4), the abrasive grains are retained or stored in the grooves, and effective processing is performed, and the processing amount is increased. Can be improved.

Further, since the fixed abrasive grains in which the resin and the abrasive particles are mixed are used for the surface member (claim 6), the surface member is deformed following the shape of the processed surface of the workpiece, and the surface member Is uniformly pressed against the machined surface, and the machined surface is efficiently and smoothly finished by the fixed abrasive grains. Furthermore, it is not necessary to supply a liquid containing abrasive grains to the entire processed surface, and the amount of expensive abrasive grains such as diamond used can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a smoothing tool according to the present invention.

2 is a schematic configuration diagram showing a smoothing process using the smoothing tool of FIG. 1. FIG.

FIG. 3 is a front view showing an embodiment of a surface member having grooves formed on its surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Smoothing tool 2 Base body 3 Elastic member 4 Surface member 5 Mounting part 6 Oscillation shaft 7 Work piece 8 Processing surface 9 Sticking plate 10 Lower shaft 11 Scan trajectory 12 Groove

Claims (9)

[Claims] 1. A smoother for smoothing while smoothing the surface to be processed while supplying a liquid containing abrasive grains to the surface to be processed.
A smoothing tool, characterized in that the smoothing tool has a diameter smaller than that of the workpiece, and a resin is used for a surface member of the smoothing tool which is pressed against the workpiece. 2. The smoothing tool according to claim 1, wherein an elastic member is provided between the surface member and a base body of the smoothing tool supporting the surface member. 3. When the processed surface of the workpiece is an aspherical surface, the surface shape of the base body supporting the surface member of the smoothing tool and / or the surface shape of the surface member is set to The smoothing tool according to claim 1 or 2, wherein the spherical surface has a spherical shape when approximated by a spherical surface. 4. The smoothing tool according to claim 1, wherein a mesh-like groove is formed on the surface of the surface member. 5. The smoothing tool according to claim 1, wherein the resin is an epoxy resin. 6. A smoothing tool for smoothing while smoothing the surface to be machined while supplying a liquid such as water to the machined surface of the machined object, wherein the smoothing tool is more than the object to be machined. Sum with a small diameter and pressure contact with the workpiece
A smoothing tool characterized in that fixed abrasives, which are a mixture of resin and abrasives, are used for the surface member of the polishing tool. 7. The smoothing tool according to claim 6, wherein an elastic member is provided between the surface member and a base body of the smoothing tool supporting the surface member. 8. When the processed surface of the workpiece is an aspherical surface, the surface shape of the substrate supporting the surface member of the smoothing tool and / or the surface shape of the surface member is set to The smoothing tool according to claim 6 or 7, wherein the spherical surface has a spherical shape when approximated by a spherical surface. 9. The smoothing tool according to claim 6, wherein the resin is an epoxy resin.